The real title here is: Don’t be a shit.
If you want to be a professional writer, be polite. No matter what. This article by Chuck Wendig (who has a potty mouth with occasional vivid sexual references – but he sure is worth listening to) is worth reading and obeying.
Here’s a bit:
Editors and agents have it tough. They get a lot of shit for being gatekeepers, but here’s what happens at the gate: they stand there, arms and mouths open while a garbage truck backs up (beep beep beep) and unloads a mountain of submissions upon them daily. And, spoiler warning, ninety percent of those submissions won’t cut it. Hell, a not unreasonable percentage are toxic enough that I’m surprised Homeland Security doesn’t show up with hazmat suits and flamethrowers. So, when you annoy them with constant emails, unedited manuscripts, work that’s already been self-published or with crazily presumptive tweets, well, it just puts them one step closer to a water tower with a rifle. I’m not saying every editor and agent is a shining example, but they don’t deserve you acting like a grit of sand in the elastic of one’s underoos.